The Coburg area belonged to the diocese of Würzburg from the Christianization of Franconia and Thuringia, probably for the first time around 768, until the introduction of the Reformation in 1524.[8] After that, the city was an almost exclusively Protestant city for over four centuries. The Lutheran faith predominated. In 1910, over 96 percent of the population were members of the Protestant regional church. The head of the regional church was the respective Duke of Saxe-Coburg as "summus episcopus". Among other things, he appointed the church governments. The spiritual leadership was provided by the superintendents based in Coburg. After the unification of Coburg with Bavaria, the Evangelical Regional Church of Coburg joined the Evangelical Lutheran Regional Church of Bavaria in 1921. Coburg is the seat of a deanery, which, with over 76,129 members (2008), is one of the largest in Bavaria.
Roman Catholic parishioners moved back to the city in the 18th century at the latest. From 1802 they were permitted to hold services, first in a room at Ketschengasse 1, and from 1806 in the Nicholas Chapel. In 1860, the approximately 600 Catholics received the new church of St. Augustine as their own church under the protection of Prince August of Saxe-Coburg-Koháry. In 1826, the parish was incorporated from the diocese of Würzburg into the archdiocese of Bamberg.[19]
In addition to the two large churches, there are also congregations that belong to free churches, including the Evangelical Free Church (Baptists), the Adventist Church (Seventh-day Adventists) and the Christian Community. In addition, a New Apostolic congregation, an Old Catholic parish in the St. Nicholas Chapel, the Church of Jesus Christ of Latter-day Saints and Jehovah's Witnesses are represented in Coburg. The villa Judaeorum (Jewish suburb) was first recorded as early as 1321. There has not been a Jewish community with a synagogue since 1941. In 2006, there were three prayer houses of Muslim communities in Coburg.